Columbus traversed the Atlantic Ocean a total of eight times, four westward and four eastward, exploring land in the Caribbean and South America and advancing the course of European New World exploration significantly. The letter up for auction is one that Columbus wrote in 1493 to Luis de Santangel, the royal treasurer to Spain's King Ferdinand II and Queen Isabella, who notably financed Columbus's voyages, beginning in 1492.

The auction house Christie's expects a haul of at least £1.2 million for the Latin translation of the letter, which survives as the echo of one of the very early printing presses. Significantly, Columbus writes that he has "taken possession for their Highnesses" of a number of lands and possessions of the "numberless people" he found in the New World.

Columbus wrote the letter from one of his original ships, the Ni¤a. It was read in the Spanish court in April 1493 and then, a month later, translated into Latin and addressed to Gabriel Sanchez. It was that Latin text that gained wide release, disseminating Columbus's experiences in the New World and firing imaginations of many looking for riches and other opportunities far to the west of Europe.

The text is known as Plannck II, an amended version of the original and so named after the publisher, Rome's Stephan Plannck. The letter had been part of a private Swiss collection for decades. No copy of the original Spanish version is known to exist.